Federer fends off Zverev to reach semis — ATP Finals

The result: Boris Becker Group:Jack Sock bt Alexander Zverev 6-4, 1-6, 6-4. I felt I was playing in a way that I also like, playing forward, playing attacking tennis.

The world number two had never lost to his opponent and all seemed to be going to plan as Federer cruised through the first set.

Dimitrov made the breakthrough after taking his second break point chance with an aggressive forehand in the eighth game. A shot through the legs by Sock in the fourth game - be it laziness or his "showtime" alter ego it isn't quite clear - either way it looked as though Sock was losing his focus and fell quickly to 4-0 down in the second. "Things really turned around for him at that moment".

By now, Sock had won more games than Dimitrov had relinquished in his previous two games combined.

The sixth seed started where he left off by making a blistering start, winning the first three games.

"That last game really took it out of me, his forehand was giving me real trouble today", Dimitrov said after the match. It could be the expectations for him, as well.

It could have gone either way, even the last rally of the match was a fraught, drop shot fuelled fight.

London [U.K], November 15 (ANI): 19-time Grand Slam Champion Roger Federer saw off a spirited challenge from 20-year-old Alexander Zverev of Germany to reach the semi-final of the season-ending ATP World Tour Finals here on Wednesday.